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Question #47581
The Question
A researcher observes two mammalian cell cultures, X and Y. Culture X forms a confluent monolayer and ceases division, while Culture Y continues to divide, forming multi-layered masses with a persistently high mitotic index. Based on the principles of cell cycle regulation and oncogenesis, which of the following statements is INCORRECT?
Options
- A.
Cells of Culture X exhibit contact inhibition and have exited the G1 phase to enter the G0 phase.
- B.
Cells of Culture X in the G0 phase are metabolically inactive and suspend proliferation until specific extracellular signals induce re-entry into the cell cycle.
- C.
Culture Y demonstrates a failure in contact inhibition, allowing cells to continuously bypass the G1/S restriction point without differentiating.
- D.
The high mitotic index in Culture Y indicates an inability to transition into the quiescent stage, a hallmark of neoplastic transformation.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Stem Cells|Quiescence|Cyclin-CDK Complex
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students frequently confuse 'quiescent' (non-dividing) with 'metabolically inactive'.
The trap exploits this common misconception.
Furthermore, the question requires cross-chapter synthesis, linking Class 11 'Cell Cycle and Cell Division' (G0 phase metabolic status) with Class 12 'Human Health and Disease' (Contact inhibition in cancer cells).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Cell Cycle and Cell Division - Class 11 |
| Concept | Mitotic Index Implications |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |